The latest release as I type this is release R2019a. Release R2019b is not out yet.
If you want to use release R2019a, check with your school / university / company's IT department first to see if you already have a license. If you do, they can tell you if you're eligible to use it and how to get access to that license if you are.
If you don't already have a license, click the "Get MATLAB" button in the upper-right corner of this page for information on how to trial or buy the software.